In your iso test shots the photographic subject has very little fine detail, whence you can only guess, how much detail is getting lost by noise reduction at high iso. In general Canon cameras favor detail over low noise, but it would be nice to see it in the tests.

The level of detail is for me always OK (till 400 iso), except maybe the loss of structure of the hair of a subject when long exposure enables the specific noise treatment (long exposure also generates noise) or when high iso setting is used.

I was the one who mentioned that tip (slow sync + -1 EV flash setting).

First point: if and when I can avoid to use the flash, I let it off. Slow sync works as a "pre-flash mixed to the ambiant light". If you set less flash power at the same time, you will avoid many "burned" pictures anda lot ofred eyes (but the Auto White Balance works then sometimes not as good as it should, so set ion manual WB). Well, it's not a magical tip but it works, especially if the room is not too dark and when the eyes of the subject have not to accomodate too much to the flash.

But the built in flash remains too close to the lense to have ALWAYS perfect results.

Night shots: not tried yet.

Lense sharpness: not tried aperture by aperture + focal by focal for theregular mode, but the macro position is really sharp at any aperture and at any focal distance, with a focus from 1 cm, really great.

I try to do the tests at the limits of the camera: so, red eye tip will function better in better light conditions than those of the test (I mean then less noise :-)). But you may prefere more definition and "flash signature", just question of choice.

IS test: again, indoor low light test was my way to push the IS to its limits. I think having a defined photo at 35 mm 80 iso with a 2.5 sec exposure proves it work very well, with an outdoor test , it would be more difficult to see the IS in action (behalve if I had a robot always making the same movements to shake the camera :O), because there the rule "do not expose slowlier than1/focal distance" would be enough to avoid blured pics most of the time (at least at the wide angle position).